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Mark Henley
Mark Henley, Journeyman Technician
Category: HVAC
Satisfied Customers: 3217
Experience:  UA Journeyman Pipefitter , HVAC, Refrigeration, DDC controls. 26 years.Commercial & residential
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I have new 16 seer Trane heat pump unit that isnt cooling

Resolved Question:

I have new 16 seer Trane heat pump unit that isn't cooling because of HPCO/error 80. My question is, after 3 failed attempts by my HVAC installer to correctly diagnose and fix the problem, I'd like to know most common scenario/cause of error 80. Is it freon pressure thats too high or suction too low? Is it the fact that the supply return distance between condenser and indoor handler is 55 feet? I'd like to be educated so I can hire the right people to fix the problem once and for all before I sheetrock in the ceiling along which my freon line runs and while I'm down to stud still. Thank you for any enlightening info.

Edward
Submitted: 7 years ago.
Category: HVAC
Expert:  Mark Henley replied 7 years ago.
<p>Hi,</p><p> </p><p>The operating conditions would have to pretty extreme for the unit to be able to provide cooling within the pressure limits of the pressure safety switch so being a hot house and a hot pull down should not have mattered at all.</p><p> </p><p>I have heard of this problem before, being solved by changing the pressure switch/sensor as i twas the sensor that was inaccurate.</p><p> </p><p>Other possible causes are having air in the system, that would be the most common reason for the failure in order to repair that they will need to recover the refrigerant and pull a good vacuum and then recharge it with virgin refrigerant. </p><p> </p><p>The other possibility is that it is just not condensing the refrigerant in the condenser, he will need subcooling readings to determine that scenario. Basically if the small copper line is hot then its not condensing properly and you will need to look into reasons for that, usually a problem with the condenser fan or the condenser being dirty. </p><p> </p><p>Those are the things to nail down, the longer line set has little to do with a high pressure problem which is what the fault relates to, its not allow pressure trip which would be for different reasons.</p><p> </p><p>Thanks</p><p> </p><p>Mark</p><p> </p><p> </p>
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Expert:  Mark Henley replied 7 years ago.
Hi,

The operating conditions would have to pretty extreme for the unit to be able to provide cooling within the pressure limits of the pressure safety switch so being a hot house and a hot pull down should not have mattered at all

I have heard of this problem before, being solved by changing the pressure switch/sensor as it was the sensor that was inaccurate

Other possible causes are having air in the system, that would be the most common reason for the failure in order to repair that they will need to recover the refrigerant and pull a good vacuum and then recharge it with virgin refrigerant.


The other possibility is that it is just not condensing the refrigerant in the condenser, he will need subcooling readings to determine that scenario. Basically if the small copper line is hot then its not condensing properly and you will need to look into reasons for that, usually a problem with the condenser fan or the condenser being dirty.

Those are the things to nail down, the longer line set has little to do with a high pressure problem which is what the fault relates to, its not allow pressure trip which would be for different reasons.

Thanks

Mark
Mark Henley and 3 other HVAC Specialists are ready to help you